1. Field of Invention
This invention relates generally to filter devices and, more particularly, to filters using scrapers or similar devices for removing particulates from a filter surface.
2. Description of Related Art
It is well-known that the mechanical cleaning of a filter surface can be accomplished by having a brush or scraper drag along the filter surface where deposits have accumulated. In certain configurations, the brush or scraper is mounted at one end between two walls but with a significant portion of the brush or scraper projecting beyond the walls. Such configurations are shown in U.S. Pat. Nos. 148,557 (Gillespie et al.); 556,725 (Farwell); 740,574 (Kohlmeyer) and 793,720 (Godbe). In conventional filter systems, the particulate contaminants are driven off the filter surface and are deposited in a hopper or tank along with some of the fluid being filtered.
Scraper edges are prone to wear over time and therefore it is necessary to periodically adjust the relative position of the scraper edge with the filter surface. In some cases, it desirable to make such adjustments without compromising or breaking the pressure boundary in the system being filtered by opening a hatch or access panel to reach the filter. This may become more complicated where such scrapers are used with filter assemblies for cleaning fuel oil in ships (see for example, U.S. Pat. Nos. 6,177,022 (Benenson, Jr. et al.); 6,517,722 (Benenson, Jr. et al.); 6,821,444 (Benenson, Jr., et al.)) because the fuel oil system is a critical system and as such the filter assemblies therein cannot be removed from service or otherwise opened for scraper adjustment. Moreover, this scraper adjustment needs to be accomplished without fasteners within, or access to, the filter assembly itself.
Thus, there remains a need for periodically adjusting the scraper position in a filter assembly without the need to have access to the scraper/filter interface, without having to depressurize the filter assembly and avoiding the use of any components that can dislodge and foul the filter system.
All references cited herein are incorporated herein by reference in their entireties.